U.S. patent number 4,814,102 [Application Number 07/175,176] was granted by the patent office on 1989-03-21 for detergents containing oxyalkylated, carboxyl-containing polymers.
This patent grant is currently assigned to BASF Aktiengesellschaft. Invention is credited to Richard Baur, Walter Denzinger, Albrecht Eckell, Heinrich Hartmann, Josef Mueller, Hans-Juergen Raubenheimer, Wolfgang Trieselt.
United States Patent |
4,814,102 |
Baur , et al. |
March 21, 1989 |
Detergents containing oxyalkylated, carboxyl-containing
polymers
Abstract
Detergents which contain from 0.01 to 20% by weight of
oxyalkylated, carbonyl-containing polymers can be prepared by
reacting. (A) a polymer which contains, as copolymerized units, one
or more monoethylenically unsaturated C.sub.3 -C.sub.6 -carboxylic
acids with (B) ethylene oxide, propylene oxide, n-butylene oxide,
isobutylene oxide or a mixture of these, in an aqueous medium at up
to 150.degree. C.
Inventors: |
Baur; Richard (Mutterstadt,
DE), Denzinger; Walter (Speyer, DE),
Eckell; Albrecht (Frankenthal, DE), Hartmann;
Heinrich (Limburgerhof, DE), Mueller; Josef
(Grosskarlbach, DE), Raubenheimer; Hans-Juergen
(Ketsch, DE), Trieselt; Wolfgang (Ludwigshafen,
DE) |
Assignee: |
BASF Aktiengesellschaft
(Ludwigshafen, DE)
|
Family
ID: |
6324810 |
Appl.
No.: |
07/175,176 |
Filed: |
March 31, 1988 |
Foreign Application Priority Data
Current U.S.
Class: |
510/360; 510/315;
510/351; 510/361; 510/469; 510/475; 510/476; 252/180 |
Current CPC
Class: |
C08F
8/14 (20130101); C11D 3/3784 (20130101); C11D
3/3757 (20130101); C11D 3/378 (20130101); C11D
3/3773 (20130101) |
Current International
Class: |
C08F
8/14 (20060101); C08F 8/00 (20060101); C11D
3/37 (20060101); C11D 017/00 () |
Field of
Search: |
;252/82,174.24,180,DIG.11 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Kirk Othmer, vol. 1, 3rd Ed., pp. 348, 354. .
Encyclopedia of Polymer Science & Engineering, 2nd Ed., vol. 1,
pp. 245 and 305..
|
Primary Examiner: Clingman; A. Lionel
Attorney, Agent or Firm: Michaels; Joseph D.
Claims
We claim:
1. A detergent comprising, as an added builder, an oxyalkylated,
carboxyl-containing polymer which can be prepared by reacting
(A) polymers which contain, as monomeric units, one or more
monoethylenically unsaturated C.sub.3 -C.sub.6 -carboxylic acids
and
(B) from 3 to 80% by weight, based on the polymers (A), of ethylene
oxide, propylene oxide, n-butylene oxide, isobutylene oxide or a
mixture of these,
in an aqueous medium at up to 150.degree. C., the builder
simultaneously being an incrustation inhibitor and a dispersant for
dirt particles in the wash liquor, and being present in the
detergent in amounts of from 0.1 to 20% by weight.
2. A detergent as claimed in claim 1, wherein the polymer (A) used
is a homopolymer of a monoethylenically unsaturated C.sub.3
-C.sub.6 -carboxylic acid.
3. A detergent as claimed in claim 1, wherein the polymer (A) used
is a copolymer of
(a) monoethylenically unsaturated C.sub.3 -C.sub.6 -monocarboxylic
acids and
(b) monoethylenically unsaturated dicarboxylic acids of 4 to 6
carbon atoms.
4. A detergent as claimed in claim 1, wherein the polymer (A) used
is a copolymer of
(a) from 5 to 40% by weight of one or more monoethylenically
unsaturated C.sub.3 -C.sub.6 -monocarboxylic acids,
(b) from 5 to 40% by weight of one or more monoethylenically
unsaturated dicarboxylic acids of 4 to 6 carbon atoms,
(c) from 0 to 80% by weight of one of more hydroxy-C.sub.2 -C.sub.6
-alkyl esters of mono- or dicarboxylic acids according to (a) and
(b) and
(d) from 0 to 20% by weight of one or more amides or nitriles of
mono- or dicarboxylic acids according to (a) and (b) or of one or
more esters of monohydric C.sub.1 -C.sub.4 -alcohols with the said
acids, vinylphosphonic acid, vinylsulfonic acid, vinyl acetate,
vinyl propionate and/or acrylamido-2-methylpropanesulfonic
acid,
the sum of the percentages by weight (a) to (d) always being
100.
5. A detergent as claimed in claim 1, wherein the oxyalkylated
carboxyl-containing polymers can be prepared by reacting (A) and
(B) in the presence of from 0.5 to 5% by weight, based on the
alkylene oxides (B) used, of thioethers of SH-containing
compounds.
6. A detergent as claimed in claim 1, wherein the oxyalkylated
polymers have a K value of from 8 to 200 (determined according to
H. Fikentscher in aqueous solution at pH 7, at 25.degree. C. and at
a polymer concentration of the Na salt of 1% by weight).
7. The detergent as claimed in claim 1, wherein the oxyalkylated
polymers have a K value of from 15 to 100 (determined according to
H. Fikentscher in aqueous solution at pH 7, at 25.degree. C. and at
a polymer concentration of the Na salt of 1% by weight).
8. A detergent as claimed in claim 1, wherein the alkali metal
and/or ammonium salts of oxyalkylated, carboxyl-containing polymers
are used.
Description
U.S. Pat. No. 3,880,765 discloses the preparation of oxyalkylated,
water-soluble polymers of acrylic acid. In a process variant
described in the U.S. Patent, polymers of acrylic acid are reacted
with from 2 to 60% by weight, based on the polymer used, of an
alkylene oxide, preferably ethylene oxide, in an aqueous medium.
The oxyalkylated polymers which can be prepared in this manner are
neutralized, for example with sodium hydroxide solution, and are
used in amounts of from 10 to 100 ppm, occasionally up to 500 ppm,
in oil production in order to prevent deposition from water onto
metallic surfaces.
It is an object of the present invention to provide an additive for
detergents which acts as a builder and has a very high dispersing
power for pigment dirt in the wash liquor.
We have found that this object is achieved, according to the
invention, by the use of oxyalkylated, carboxyl-containing polymers
which can be prepared by reacting
(A) a polymer which contains, as monomeric units, one or more
monoethylenically unsaturated C.sub.3 -C.sub.6 -carboxylic acids
with
(B) from 3 to 80% by weight, based on the polymer (A), of ethylene
oxide, propylene oxide, n-butylene oxide, isobutylene oxide or a
mixture of these,
in an aqueous medium at up to 150.degree. C., as an additive in
detergents in amounts from 0.1 to 20% by weight.
Suitable polymers (A) are homopolymers of monoethylenically
unsaturated C.sub.3 -C.sub.6 -carboxylic acids or copolymers which
contain, as monomeric units, not less than 20% by weight of a
monoethylenically unsaturated C.sub.3 -C.sub.6 -carboxylic acid.
Suitable monoethylenically unsaturated carboxylic acids of this
type are, for example, acrylic acid, methacrylic acid, ethacrylic
acid, vinylacetic acid, allylacetic acid, propylideneacetic acid,
ethylidenepropionic acid, mesaconic acid, fumaric acid,
methylenemalonic acid, citraconic acid, maleic acid and itaconic
acid. Among the stated carboxylic acids, acrylic acid, methacrylic
acid, maleic acid, fumaric acid, itaconic acid or a mixture of
these is preferably used.
Other suitable polymers (A) are copolymers of
(a) monoethylenically unsaturated C.sub.3 -C.sub.6 -monocarboxylic
acids and
(b) monoethylenically unsaturated dicarboxylic acids of 4 to 6
carbon atoms.
Preferably used monomers of group (a) are acrylic acid and/or
methacrylic acid. Examples of monomers of group (b) are maleic
acid, itaconic acid, mesaconic acid, fumaric acid, methylenemalonic
acid and citraconic acid. Maleic acid is preferably used from this
group of monomers. The copolymers contain, as copolymerized units,
from 1 to 99% by weight of the monomers of group (a) and from 99 to
1% by weight of the monomers of group (b).
The carboxyl-containing copolymers can be modified by
copolymerization with further monomers. Copolymers of this type
contain, as monomers,
(a) from 5 to 40% by weight of one or more monoethylenically
unsaturated C.sub.3 -C.sub.6 -monocarboxylic acids, preferably
acrylic acid and/or methacrylic acid,
(b) from 5 to 40% by weight of one or more monoethylenically
unsaturated dicarboxylic acids of 4 to 6 carbon atoms, preferably
maleic acid and/or itaconic acid,
(c) from 0 to 80% by weight of one or more hydroxy-C.sub.2 -C.sub.6
-alkyl esters of mono- or dicarboxylic acids according to (a) and
(b) and
(d) from 0 to 20% by weight of one or more amides or nitriles of
mono- or dicarboxylic acids according to (a) and (b) or of one or
more esters of a monohydric C.sub.1 -C.sub.4 -alcohol with the said
acids, vinyl acetate, vinyl propionate, vinyl-phosphonic acid,
vinyl sulfonate and/or acrylamido-2-methylpropanesulfonic acid.
The sum of the percentages by weight (a) to (d) is always 100.
Examples of suitable monomers (c) are hydroxyethyl acrylate,
hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl
methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate,
hydroxyhexyl acrylate, monohydroxyethyl maleate, hydroxyethyl
maleate, monohydroxypropyl maleate, dihydroxypropyl maleate,
monohydroxybutyl maleate, dihydroxybutyl maleate, monohydroxyethyl
itaconate, dihydroxyethyl itaconate, monohydroxypropyl itaconate,
dihydroxypropyl itaconate and monohydroxybutyl itaconate. Among the
hydroxyalkyl esters which are derived from diols 3 to 6 carbon
atoms, all isomers can be used. Preferably used monomers of group
(c) are hydroxyethyl acrylate, hydroxyethyl methacrylate,
hydroxypropyl acrylate, hydroxybutyl acrylate and hydroxypropyl
methacrylate. The monomers of group (c) are preferably present in
the copolymers in an amount of from 20 to 60% by weight.
Examples of suitable components (d) are acrylamide, methacrylamide,
acrylonitrile, methacrylonitrile, acrylates of alcohols of 1 to 4
carbon atoms, e.g. methyl acrylate, ethyl acrylate, n-propyl
acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate
and tertbutyl acrylate, and the corresponding esters of methacrylic
acid and monoesters of dicarboxylic acids, such as monomethyl
maleate, dimethyl maleate, monoethyl maleate, mono-n-propyl
maleate, diisopropyl maleate, mono-n-butyl maleate, mono-sec-butyl
maleate, di-n-propyl maleate, di-n-butyl maleate and di-sec-butyl
maleate, and the corresponding esters of fumaric acid and itaconic
acid, vinyl acetate, vinyl propionate, vinylphosphonic acid,
vinylsulfonic acid and/or acrylamido-2-methylpropanesulfonic acid.
If the copolymers are modified with monomers of group (d), the
amount of monomers of group (d) in the copolymers is up to 20,
preferably from 5 to 15, % by weight.
The abovementioned homo- and copolymers have weight average
molecular weights of from 500 to 1 million, preferably from 10,000
to 500,000. The polymers are characterized below by the Fikentscher
K value, instead of the molecular weight. The K value of the homo-
and copolymers is from 8 to 200, preferably from 15 to 100. It is
determined according to H. Fikentscher in 1% strength aqueous
solution at pH 7, 25.degree. C. and a polymer concentration of the
sodium salt of the polymer of 1% by weight.
The polymers (A) described above, which contain not less than 20%
by weight of a monoethylenically unsaturated C.sub.3 -C.sub.6
-carboxylic acid as monomeric units, are reacted, in the form of
the free acid groups or in partially neutralized form, with
alkylene oxides in an aqueous medium. If, apart from carboxyl
groups, the polymers (A) do not contain any functional groups which
react with the alkylene oxides, the maximum degree of
neutralization is 70 mol %. However, if the polymers A contain not
only carboxyl groups but also, for example, hydroxyl groups, all
the carboxyl groups of these polymers can also be neutralized. In
this case, the alkylene oxides are added at the hydroxyl groups of
the copolymers. The polymers (A) are preferably subjected to the
oxyalkylation in the form of the free acids, for which purpose they
are dissolved in an aqueous medium. The polymer concentration is
from 5 to 90, preferably from 20 to 70, % by weight. A preferably
used aqueous medium is pure water, for example river water freed
from suspended substances, demineralized water or distilled water.
Other suitable aqueous media are mixtures of water and solvents
which are water-soluble, for example alcohols, such as methanol,
ethanol, n-propanol and isopropanol, acetone, dimethylformamide,
dioxane and tetrahydrofuran. The water-miscible solvents are used
especially when the polymers (A) do not dissolve completely in
water. Of course, it is also possible to use mixtures of organic
solvents and water as the aqueous medium. The content of organic
solvent in the solvent mixtures can be up to 50% by weight.
The polymers of group (A) are reacted with the alkylene oxides
mentioned above under (B). These alkylene oxides are ethylene
oxide, propylene oxide, n-butylene oxide, isobutylene oxide or
mixtures of the stated alkylene oxides. The reaction of the
polymers with the alkylene oxides is carried out in an aqueous
medium at from 5.degree. to 150.degree. C., preferably from
10.degree. to 80.degree. C., under atmospheric or superatmospheric
pressure. If the reaction is carried out under superatmospheric
pressure, the pressures are up to 50 bar. The reaction is usually
carried out under up to 20 bar. The alkylene oxide or a mixture of
the alkylene oxides is subjected to an addition reaction with the
polymers. Small amounts of diols are formed as byproducts. The diol
formation, which results from the addition reaction of water with
the alkylene oxides, can be suppressed by carrying out the reaction
of the polymers (A) and the alkylene oxides (B) in the presence of
from 0.5 to 5% by weight, based on the alkylene oxides used, of
thioethers or SH-containing compounds. Examples of suitable
thioethers are those of the general formula R--S--R.sup.1, where R
and R.sup.1 are each C.sub.1 -C.sub.10 -alkyl, --C.sub.6 H.sub.5,
--CH.sub.2 --C.sub.6 H.sub.5, --CH.sub.2 --COOH,.sub.2 --CH
--(CH.sub.2n --COOH or --(CH.sub.2).sub.n --CH.sub.2 --OH, and n is
from 1 to 8. Examples of such thioethers are dimethyl sulfide,
diethyl sulfide, methyl phenyl sulfide, thiodiacetic acid,
thiodibutyric acid, ethylthioethanol and thiodiglycol. Thioglycol,
thioethanol, thioacetic acid, thiobutyric acid and dodecyl
mercaptan are also suitable. The pH of the reaction mixture at
20.degree. C. is not more than 6, preferably from 0.5 to 5. In the
case of the hydroxyl-containing polymers, pH >6 may also be
used. The reaction is preferably carried out under superatmospheric
pressure. The procedure used is as follows: either some or all of
the polymers (A) is dissolved in the aqueous medium and the
solution initially taken in a pressure vessel, after which some or
all of the alkylene oxide is forced in. In order to permit the heat
of reaction to be removed readily, the alkylene oxide is metered in
a little at a time or continuously at the rate at which the
reaction progresses. Advantageously, thorough mixing of the
components is ensured during the entire duration of the reaction,
for example by stirring. Autoclaves which are equipped with a
stirrer and with heating and cooling means are preferably used. It
is sometimes advantageous to add the alkylene oxide at a low
temperature and then to increase the temperature to complete the
reaction, for example to meter in the alkylene oxide at 40.degree.
C. and then to allow the reaction to continue at 80.degree. C. When
the reaction is complete, oxyalkylated carboxyl-containing polymers
are obtained and can be used directly in detergents, in this form
or after neutralization. However, the reaction products can also be
isolated from the aqueous solution and incorporated in solid form,
for example as pellets or flakes, into detergent formulations.
The oxyalkylated carboxyl-containing polymers are neutralized
using, for example, sodium hydroxide solution, potassium hydroxide
solution, ammonia or an amine, for example a C.sub.1 -C.sub.18
-alkylamine, such as ethylamine, propylamine, butylamine,
dibutylamine, hexylamine, stearylamine, ethanolamine, morpholine,
diethanolamine or triethanolamine.
Up to 80, preferably from 20 to 60, mol % of the carboxyl groups of
the polymers (A) are reacted with the alkylene oxides. This
proportion corresponds to an amount of from 3 to 80, preferably
from 6 to 60, % by weight, based on polymers (A), of alkylene
oxides.
The oxyalkylated carboxyl-containing polymers are added to
detergents in an amount from 0.1 to 20, preferably from 1 to 15, %
by weight. In wash liquors, they act as builders and incrustation
inhibitors and as dispersants for dirt particles which are detached
from the textile material and are present in the wash liquor.
The oxyalkylated, carboxyl-containing polymers can be added,
according to the invention, to both phosphate-containing and
phosphate-free detergents. The phosphorus-containing detergents
have a reduced phosphate content of less than 25% by weight of
sodium triphosphate. The oxyalkylated polymers are added to the
detergent formulation in the form of a solution or as a mixture
with other components, for example together with standardizing
agents, such as sodium sulfate, or builders (zeolites) or other
assistants. The products to be used according to the invention can
be added to both detergent powders and liquid detergent
formulations.
Commercial detergent powders which either contain sodium
triphosphate or are phosphate-free possess, as an important
component, surfactants, e.g. C.sub.8 -C.sub.12 -alkylphenol
oxyethylates, C.sub.12 -C.sub.20 -alkanol oxyethylates, and block
copolymers of ethylene oxide and propylene oxide. The polyalkylene
oxides are solids from room temperature to 50.degree. C. and
readily soluble or dispersible in water. They are linear or
branched reaction products of ethylene oxide with propylene oxide
and/or isobutylene oxide, which have a block structure or may have
a random structure. The terminal groups of the polyalkylene oxides
can, if required, be blocked, i.e. the free OH groups of the
polyalkylene oxides can be etherified and/or esterified and/or
aminated and/or reacted with isocyanates.
Anionic surfactants, such as C.sub.8 -C.sub.12
-alkylbenzenesulfonates, C.sub.12 -C.sub.16 -alkanesulfonates,
C.sub.12 -C.sub.16 -alkylsulfates, C.sub.12 -C.sub.16
-alkanesulfosuccinates and sulfated oxyethylated C.sub.12 -C.sub.16
-alkanols are also suitable components of detergent powders. The
detergent powders may furthermore contain polycarboxylic acids or
their salts, for example tartaric acid or citric acid. The
detergent powders usually contain from 5 to 20% by weight of
surfactants.
Another important component of detergent formulations comprises
incrustation inhibitors. These substances are, for example,
homopolymers of acrylic acid, methacrylic acid and maleic acid or
copolymers, for example copolymers of maleic acid and methacrylic
acid, copolymers of maleic acid and acrylic acid or copolymers of
acrylic and/or methacrylic acid and acrylates, methacrylates, vinyl
esters, allyl esters, itaconates, itaconic acid, methylenemalonic
acid, methylenemalonates, crotonic acid or crotonates. Other
suitable copolymers are those obtained from maleic acid and olefins
of 2 to 18 carbon atoms and/or C.sub.1 -C.sub.4 -alkyl vinyl
ethers. The molecular weight of the homo- and copolymers is from
1,000 to 100,000. The incrustation inhibitors are used in an amount
of from 0.5 to 10% by weight in detergents, and are employed in the
unneutralized form, as an alkali metal or ammonium salt or in
partially neutralized form, for example where from 40 to 60% of the
carboxyl groups are neutralized.
Other possible components of detergents are corrosion inhibitors,
monomeric, oligomeric and polymeric phosphonates, ether sulfates
based on unsaturated fatty alcohols or their alkali metal salts.
Detergent powders may alternatively also contain zeolites. If
zeolites are used, the amount of the latter is from 5 to 30% by
weight, based on the total detergent formulation. The detergent
formulations can also contain bleaching agents in an amount of from
3 to 25% by weight, for example sodium perborate, as well as bleach
activators, plasticizers, antifoams, perfume, optical brighteners
and enzymes. Standardizing agents, such as sodium sulfate, may be
present in the detergent in an amount of up to 40% by weight.
The oxyalkylated carboxyl-containing polymers to be used according
to the invention can also be employed as additives for liquid
detergents. The liquid detergents contain, as essential components,
surfactants which are solid or liquid at room temperature and are
soluble or dispersible in the detergent formulation. Suitable
surfactants for this purpose are the products which have also been
used in detergent powders, as well as liquid polyalkylene oxides
and polyoxyalkylated compounds. The surfactant content of liquid
detergents can be from 5 to 50%, depending on the type of liquid
detergent.
The oxyalkylated polymers to be used according to the invention
exhibit, both in phosphate-free and phosphate-containing detergent
formulations, an action which is similar to that of the most
effective commercial polymeric incrustation inhibitors and moreover
have a greatly improved dispersing power for the dirt particles
detached from the wash during washing.
In the Examples which follow, parts and percentages are by weight.
The K values of the carboxyl-containing copolymers were measured
according to H. Fikentscher, Zellulosechemie, 13 (1932), 58-64 and
71-74, in aqueous solution at 25.degree. C., at a polymer
concentration of 1% by weight of the sodium salt and at pH 7;
K=k.10.sup.3. The Fikentscher K-value is an art recognized and
accepted indication of relative molecular weights of polymers and
is described in "Vinyl and Related Polymers"by Schidlkneckt, John
Wiley and Sons, New York 11, N.Y. 1952, at page 676.
EXAMPLES
Preparation of the oxyalkylated, carboxyl-containing polymers
The polymer solution stated in Table 1 and the catalyst likewise
noted there are introduced into a 6 l autoclave capable of being
heated and cooled and equipped with a stirrer and metering
apparatuses. The autoclave is then closed so that it is
pressure-tight. Thereafter, nitrogen is forced in three times until
a pressure of 4 bar is reached, the autoclave being let down after
each feed process. The autoclave is then brought to a nitrogen
pressure of 2 bar, and the autoclave content is heated to the
reaction temperature stated in the Table. After the reaction
temperature has been reached, the alkylene oxide stated in Table 1
is metered in via a pressure vessel. The resulting heat of reaction
is removed by cooling the autoclave. The reaction is substantially
complete about a 1/4 of an hour after the end of the alkylene oxide
addition. The stirred autoclave content is then heated for a
further 2 hours, after which the reaction mixture is cooled to
give, in each case, an aqueous solution, whose solids content is
determined by drying for 2 hours at 150.degree. C. in a drying
oven. The alkylene glycol contents in the reaction mixture, which
are likewise shown in Table 1, were determined by gas
chromatography.
TABLE 1
__________________________________________________________________________
Carboxyl-containing polymer used Feed time for Polymer Amount
Alkylene Catalyst Temp. alkylene oxide No. [g] oxide [g] [g]
[.degree.C.] [h]
__________________________________________________________________________
1 2147 Copolymer of 50% by weight 155 PO 3.1 80 0.5 of AA and 50%
by weight of thiodiglycol MA, 50% neutralized with NaOH, 42.6%
strength solution in water, pH = 4.5, K value: 54 2 2009 Copolymer
of 70% by weight 246 PO 4.9 30 2 of AA and 30% by weight of
ethylthio- MA, 30% neutralized with ethanol NaOH, 45.3% strength
solution in water, pH = 3.9 K value: 66 3 2107 Copolymer of 50% by
weight 321 PO 6.5 35 2.5 of AA and 50% by weight of thiodiacetic
MA, 50.5% strength solution acid in water, pH = 0.7, K value: 20 4
3529 Copolymer as for Polymer 2 518 BuO 10.5 45 5 thiodiglycol 5
2107 Copolymer as for Polymer 3 244 EO 4.5 45 2.5 thiodiglycol
__________________________________________________________________________
K value of the Alkylene glycol Polymer Appearance of solution
Solids content [%] pH of the oxyalkylated formed as by-product No.
of oxyalkylated polymer of the solution solution polymer [%]
__________________________________________________________________________
1 yellow, clear, 45.2 4.9 56 2.6 propylene glycol viscous 2
yellowish, clear, 49.9 4.3 69 3.3 propylene glycol viscous 3
yellow, clear, 53.6 1.2 18 3.4 propylene glycol viscous 4
yellowish, clear, 50.6 4.3 72 2.6 1,2-n- viscous butylene glycol 5
yellow, clear, 52.3 0.9 17.5 2.1 ethylene glycol viscous
__________________________________________________________________________
MA: maleic acid AA: acrylic acid EO: ethylene oxide PO: propylene
oxide BuO: 1,2n-butylene oxide
The polymers 1 to 5 to be used according to the invention are
subjected to the test methods (1) to (4) described below. The
measurement results obtained are summarized in Table 2.
(1) Determination of the dispersing capacity for calcium phosphate
and for calcium diphosphate
Principle of measurement:
The inhibiting effect of complex formers or dispersants on the
precipitation of calcium phosphate or diphosphate is determined by
turbidity titration. The substance to be investigated is initially
taken, and titrated in the presence of sodium phosphate or
diphosphate with calcium acetate solution. The end point is
indicated by the formation of the calcium phosphate or diphosphate
precipitate. By using a sufficient amount of phosphate/diphosphate,
it is possible to ensure that the measurement gives a correct
result even when the effect is based not only on complexing of the
calcium ions but also on dispersing of calcium phosphate or
diphosphate. If in fact the amounts of phosphate used are too
small, there is a danger that the dispersing power of the product
will not be exhausted; in this case, the end point of the titration
is indicated by precipitation of the calcium salt of the
product.
During the titration, the change in the light transmission is
monitored either visually or with the aid of a lightguide
photometer. In the latter case, a light beam passed into the
solution via glass fibers is reflected by a mirror, and the
intensity of the reflected light is measured.
Reagents:
4.4% strength calcium acetate solution
sodium phosphate
or sodium diphosphate
1N sodium hydroxide solution
1% strength HCl
Procedure:
0.5 g of active substance (a.s., calculated as Na salt) are
dissolved in 100 ml of distilled water, after which 0.5 g of sodium
phosphate or diphosphate is added. The pH is brought to the desired
value and is kept constant during the titration. Standard
conditions at room temperature (RT) and pH 11.0.
Titration is carried out against 4.4% strength calcium acetate
solution at a feed rate of 1 ml/min, until permanent turbidity is
obtained, or, in the case of automatic titration (Titroprocessor),
at 0.4 ml/min.
In the case of automatic titration, the first point of deflection
of the titration curve is the end point.
Calculation: ##EQU1##
(2) Testing the incrustation inhibition by turbidity
measurement
Wash liquors become cloudy when stored at elevated temperatures, as
a result of precipitation of sparingly soluble detergent
components. The final turbidity after 2 hours is a measure of the
precipitation-inhibiting activity of the incrustation
inhibitors.
A phosphate-free model wash liquor prepared using 6.5 g/l of
detergent and having the following composition is used for the
test:
2.7% by weight of sodium C.sub.12 -alkylbenzenesulfonate
3.2% by weight of the adduct of 25 moles of ethylene oxide with 1
mole of tallow fatty alcohol,
10.8% by weight of Na metasilicate,
27.0% by weight of sodium carbonate,
2.1% by weight of CMC (carboxymethylcellulose),
3% by weight of polymer and
51.2% by weight of sodium sulfate.
Storage at elevated temperatures is effected at 90.degree. C. in
water of 22.4.degree. German hardness (Ca:Mg=3:1) over a period of
2 hours.
The turbidity measurement is carried out by nephelometry [low
turbidity values (NTU) denote effective products and high values
not very effective products].
(3) Testing the dispersing power for pigment dirt
0.1 g of pigment dirt consisting of
86% of kaolin,
8% of lamp black,
4% of iron oxide black and
2% of iron oxide yellow
are dispersed together with 3 g (a.s.) of polymer in 100 ml of
water of 20.degree. German hardness (Ca:Mg=3:1) for 1 minute in a
dispersing apparatus at 2,000 rpm. The dispersion is then stored at
RT for 21 days in a cylinder.
The stability of the dispersion is assessed visually and is rated
according to the following scale:
very good: 100% dispersion
good: 75% dispersion
satisfactory: 50% dispersion
sufficient: 25% dispersion
insufficient: 0% dispersion, settled out
(4) Testing the incrustation inhibition in the wash test
To test the efficiency of the polymers, a series of 10 washes were
carried out in a Launder-o-meter, and the changes in the ash
content were used as a measure of the efficiency of incrustation
inhibition.
Test conditions
Liquor: 250 ml
Liquor ratio: 1:12.5
Water hardness: 22.4.degree. German hardness (Mg)
Duration: 30 minutes
Temperature: 35.degree.-60.degree. C. (temperature program)
Test fabric: 10 g of gray cotton cloth+10 g of cotton cheesecloth
terry towelling
Detergent: 8 g/l
Composition:
14.8% of Na C.sub.12 -alkylbenzenesulfonate (50% strength aqueous
solution),
4.6% of the adduct of 7 moles of EO with C.sub.13/15 -fatty
alcohol,
2.8% of soap,
23.1% of zeolite,
11.1% of sodium carbonate,
5.6% of Na metasilicate,
0.9% of Mg silicate,
18.5% of sodium perborate,
9.3% of sodium sulfate and
9.3% of polymer
TABLE 2
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Results Example No. Test method ##STR1## ##STR2##
[NTU]measurementby turbidityinhibitionincrustationTest of(2)
pigment dirtpower fordispersingTest cheeseclothtowellingC
ottonTerry-% ashin LaunderometerIncrustat ion
__________________________________________________________________________
1 Polymer 1 759 213 180 very good 1.68 3.30 2 Polymer 2 2392 286
160 very good 2.05 3.84 3 Polymer 3 910 244 130 good 1.54 4.10 4
Polymer 4 2028 255 180 very good 2.03 4.17 5 Polymer 5 1394 192 160
good 1.78 3.65 Comp. Ex. 1 Commercial 104 152 270 insufficient 1.61
4.01 incrustation inhibitor (copolymer of maleic acid and acrylic
acid) Comp. Ex. 2 no additive -- -- -- -- 3.97 8.03
__________________________________________________________________________
The polymers 1 to 5 used according to the invention give
substantially reduced ash values in phosphate-free formulations in
wash tests, in combination with greatly improved dispersing power
for the dirt particles detached from the wash, compared with the
commercial incrustation inhibitor. In reduced-phosphate
formulations too, the said polymers give reduced ash values which
are comparable with the values obtained using the stated commercial
polymeric incrustation inhibitor. Surprisingly, however, the
dispersing power of the novel oxyalkylated polymers for calcium
phosphate and calcium diphosphate is also greatly improved.
* * * * *